Mechanical linkages for controls on bicycles

Abstract

Conventional linkages between bicycle handlebar-mounted controls and rear brakes and gears are unable to accommodate unlimited rotation of the handlebars as is required on some so-called “freestyle” bicycles. A prior attempt to solve the problem employs a linkage comprising a bearing having two parts that are relatively rotatable about an axis. However this proposal is unable to handle situations where there are two or more mechanisms to be controlled e.g. a rear brake and a gear. The problem is solved by using multiple bearings ( 15, 16, 17 ) that share a common axis (X-X) of rotation but are located at different radial positions with respect to the axis. This avoids interference between the different linkages and makes it possible to locate the linkages around a stem on which the front wheel fork of the bicycle is mounted. A possible suitable location may be within a head tube of the bicycle frame. The invention is not limited to use with bicycles and can be employed in robotic and other machines.

1. A control device for a machine having a first part and a second part mounted for swiveling movement about an axis relative to the first part, said control device comprising:
 a first mechanical linkage acting between a first linkage controlling mechanism fixed relative to a first part of a machine and a first linkage controlled mechanism fixed relative to a second part of the machine, said first mechanical linkage comprising a first linkage bearing having at least two parts relatively rotatable about an axis and connected respectively to said first linkage controlling and first linkage controlled mechanisms; and 
 a second mechanical linkage acting between a second linkage controlling mechanism fixed relative to said first part of said machine and a second linkage controlled mechanism fixed relative to said second part of said machine, said second mechanical linkage comprising a second linkage bearing located radially outward of said first linkage bearing and having at least two parts relatively rotatable about said axis and connected respectively to said second linkage controlling and controlled mechanisms; 
 wherein said first linkage bearing and said second linkage bearing being arranged, one within another, so that said first linkage and second linkage bearings do not occupy an excessive dimension in an axial direction. 
 
     
     
       2. The control device according to  claim 1  further comprising a third mechanical linkage acting between a third linkage controlling mechanism fixed relative to said first part and a third linkage controlled mechanism fixed relative to said second part, said third mechanical linkage comprising a third linkage bearing located radially outward of said first linkage bearing and having at least two parts relatively rotatable about said axis and connected respectively to said third linkage controlling and controlled mechanisms. 
     
     
       3. The control device according to  claim 2 , wherein that each of said first, second and third linkages acts between controlling and controlled mechanisms fixed to relatively rotatable parts of said machine. 
     
     
       4. The control device according to  claim 3 , wherein said machine is a bicycle, said first part comprising a front wheel support, and said second part comprising a frame of said bicycle. 
     
     
       5. The control device according to  claim 4 , wherein said first, second and third linkage bearings surround a stem that connects a front wheel fork to a handlebar. 
     
     
       6. The control device according to  claim 5 , wherein said first, second and third linkage bearings are enclosed within a head tube in which said stem is rotatably mounted. 
     
     
       7. The control device according to  claim 5 , wherein said first linkage controlled mechanism is selected from the group consisting of a rear brake, and gears. 
     
     
       8. The control device according to  claim 5 , wherein said second linkage controlled mechanism is selected from the group consisting of a rear brake, and gears. 
     
     
       9. The control device according to  claim 5 , wherein said third linkage controlled mechanism is selected from the group consisting of a rear brake, and gears. 
     
     
       10. A bicycle control device comprising:
 an upper bearing assembly attachable to at least three linkages, and a lower bearing assembly attachable to at least three linkages; 
 at least four cylindrical guides of progressively increasing diameter, at least a first and second of said cylindrical guides being fixed relative to said upper bearing assembly, and at least a third and fourth of said cylindrical guides being fixed relative to said lower bearing assembly, said cylindrical guides defining therebetween each a channel, said channels each having an annular cross-section for guiding an axial annular bearing; and 
 a bearing guidable by each of said channels defined by said cylindrical guides, said bearings each comprising: 
 an upper ring having an outer surface formed with a recess fitted with an upper ring ball race; 
 a lower ring having an inner surface formed with a recess fitted with a lower ring ball race; 
 a plurality of balls held between said upper and lower ring ball races; 
 at least one upper roll pin receivable in a bore defined through said upper ring and said upper ring ball race for locking said upper ring and said upper ring ball race together, said upper roll pin projecting from a surface of said upper ring into a respective slot in at least one of said first and second cylindrical guides; and 
 at least one lower roll pin receivable in a bore defined through said lower ring and said lower ring ball race for locking said lower ring and said lower ring ball race together, said lower roll pin projecting from a surface of said lower ring into a respective slot in at least one of said third and fourth cylindrical guides; 
 wherein said bearings each having a diameter different from the remaining said bearings. 
 
     
     
       11. The bicycle control device according to  claim 10 , wherein said upper bearing assembly defining a conical central opening clampable to a stem of a bicycle. 
     
     
       12. The bicycle control device according to  claim 11 , wherein said bearings are enclosed within a head tube in which said stem is rotatably mounted. 
     
     
       13. The bicycle control device according to  claim 10  further comprising a washer fittable between said upper and lower ball races of each of said bearings to transmit compression forces through said bearing. 
     
     
       14. The bicycle control device according to  claim 10 , wherein said linkages attachable to said upper and lower bearing assemblies are selected from the group consisting of Bowden cables, mechanical, electro-mechanical, pneumatic, and hydraulics. 
     
     
       15. The bicycle control device according to  claim 10 , wherein said linkages attachable to said upper bearing assembly are linked to a mechanism selected from the group consisting of a rear brake, and gears. 
     
     
       16. The bicycle control device according to  claim 10 , wherein said linkages attachable to said lower bearing assembly are linked to a mechanism selected from the group consisting of a rear brake, and gears.